Yes, just make sure to not mess up the gamemode and if you want your addition to be compatible with the base version contact me here or on discord. I'll try to update the base version with your code.

If I have time, and if I'm not borred. If you want to make your own it's actually easy, there should be a mission maker helper

To save your progress you need to have your option "Gameplay" > "Custom Games - Workshop" > "Enable Workshop Inspector" and "Enable Workshop Inspector Log File" on "on" or Copy the inspector logs in game.
Then with your log, open it, get rid of the timestamp to only have lines of code.
With your lines of code, you copy and paste them in the workshop of your lobby.
Unfortunately you'll have to do it for every games because you can't save anything between games

Bc I'm lazy